The invention relates generally to a tubular housing used to support an object within the hollow interior of the tubular housing. In particular, the invention relates to a system having a tubular housing, such as a wellhead, to support an assembly, such as a casing hanger, within the tubular housing via a load member that is actuated to extend between the housing and the assembly.
In the oil and gas industry, pipes and tubing are used to transport oil and/or gas. In a well, pipe and/or tubing may be supported by a tubular housing. For example, a wellhead and a casing hanger disposed within the wellhead may be used to support pipe, known as casing, within a wellbore. Casing is strong steel pipe that is used in an oil and gas well to ensure a pressure-tight connection from the surface to the oil and/or gas reservoir. However, casing can be used to serve many purposes in a well. For example, the casing can be used to protect the wellbore from a cave-in or from being washed out. The casing can also be used to confine production to the wellbore, so that water does not intrude into the wellbore from a surrounding formation or, conversely, so that drilling mud does not intrude into the surrounding formation from the wellbore. The casing can also provide an anchor for the components of the well.
Several sections of casing joined together end-to-end are known as a “casing string.” Because casing serves several different purposes in a well, it is typical to install more than one casing string in a well. Casing strings typically are run in a concentric arrangement, similar to an upside-down wedding cake, with each casing string extending further downward into the ground as the center of the arrangement of concentric casing strings is approached. For example, the casing string with the greatest diameter typically is the outermost casing string and the shortest, while the casing string with the smallest diameter typically is at the center and extends the deepest.
The casing hanger typically supports the casing string from a wellhead or a similar structure located near the seafloor. The casing hanger rests on a landing shoulder inside the wellhead. Multiple casing hangers may supported within a single wellhead. However, another method that may be used to support a casing hanger, rather than by using a shoulder of the wellhead, is to use a load ring to support the casing hanger. The load ring may be actuated to extend between the casing hanger and a recess in the wellhead to support the casing hanger.
Unfortunately, problems may occur when engaging the load ring and installing the seal. For example, the load ring may not properly engage the wellhead. Furthermore, subsea oil and gas wells are being developed at ever increasing seawater depths. These greater ocean depths make it difficult for an operator on the surface to obtain a positive indication that a load ring, or any other such device, has been actuated in a subsea well.
Therefore, an improved technique for actuating a device in a subsea well is desired. The techniques described below may solve one or more of the problems described above.